Sentinel Chicken Surveillance Program
By: Teahna Ratliff
Mosquito-borne Disease transmission is a real concern throughout the world. Many people do not realize that West Nile Virus (WNv), Eastern Equine Encephalitis (EEE), and St. Louis Encephalitis (SLe) are transmitted from infected wild birds. “Bridge vector” mosquitoes will bite the birds then transmit the disease to other birds, horses, and humans. Sentinel chickens are on the front line for monitoring and defense against these diseases. Chickens are a “dead-end host”, just like people. They can catch the diseases, but the virus is unable to replicate enough in the bloodstream to be passed along. However, chickens are “asymptomatic” meaning they have no symptoms from the virus and do not get sick.
Most counties across Florida use the sentinel chicken program with the goal of predicting if people are at risk for mosquito-borne diseases. Chickens are strategically placed throughout the counties. Every week, mosquito control districts draw the chicken’s blood to test for the above diseases. This allows mosquito control to create “heat-maps” of where disease is likely to get passed along to humans. This data allows mosquito control to focus its treatment efforts to areas of concern.
South Walton County Mosquito Control District has 10 coop sites across the county, with a total of 60 chickens. Between March and November, the chickens are monitored to see if viruses are circulating in the area. The technicians perform phlebotomy on the chickens and collect mosquitoes from the trap beside the coops. When a chicken tests positive for a disease, we look at the species of mosquitoes from the trap. By understanding which species, we know when the mosquitoes are active to treat with adulticide and where the mosquitoes breed for larvicide purposes.
South Walton County Mosquito Control District’s number one goal is to prevent and minimize potential mosquito-borne diseases in people and animals of South Walton.